What is "VCI" Volatile Corrosion Inhibitor?
The term "VCI" stands for Volatile Corrosion Inhibitor
Rust preventive Solution…
Corrosion-inhibiting compounds vaporize from the paper or film. They are attracted to the charged surface of the metal by their polar orientation.
VCI FUNCTIONING
The VCI molecules align on the surface of the metal to a depth of 3 to 5 molecules. This layer of molecules passivates the charged surface and creates a barrier that prevents oxidation.
The corrosion cell (the flow of electrons in the metal and the flow of ions in the electrolytic surface layer) is unable to establish itself.
The VCI molecules migrate into recesses and hard to reach areas on even the most complex shapes.
The molecules build up on the metal surface until a continuous barrier has formed on the metal part.
When metals are wrapped or packaged in VCI, the chemicals volatilize in the packaging environment, forming a protective molecular layer on the surface of the metal.
This protective layer serves as a barrier, preventing moisture, salt, dirt, oxygen, and other corrosion causing materials from depositing directly on the metal and causing rust and corrosion.
Applications:
1. VCI film protective packaging
The VCI polyethylene anti-rust film protects the metallic components against corrosion, having a higher mechanical power, compared to the anti-rust paper.
During the fabrication process, the polyethylene molecules are mixed with the VCI anti-corrosion ones. The final product becomes impermeable. As against paper, the film doesn’t allow the moisture transfer, functioning like an umbrella. The VCI particles are gradually released, slower than for paper. The molecules reach the product’s surface in approximately 2 hours. It is recommended for applications where the parts can, or even must stay longer inside the factory, after they are produced, or the temperature changes from the storage/ loading for transportation area are not sudden.
The VCI polyethylene anti-corrosive foil is available in stripes with widths between 200 mm and 6000 mm. It is transparent, with a light-blue nuance. Can be used to protect ferrous and non ferrous products and metals, and doesn’t influence the mechanical or electric characteristics of the packed components.
It is very easy and quick to use, being available also as bags with different dimensions. Can be used in combination with the VCI anti corrosion paper for shipping with high humidity/ salinity conditions, like the sea transportation for example.
2. VCI paper protective packaging
VCI anti-rust packaging guarantees optimal protection against corrosion for metallic components. These products are treated with anti-corrosion molecules to offer protection for ferrous and non-ferrous items. The paper is not bleached with chlorine, being safe for use in different applications. The anti-rust properties are active for one year. The paper has the highest quantity of molecules per cm².
It is recommended for applications where the temperature differences between fabrication and packing, and transportation moment, are high. For example, if the pieces need to exit the factory immediately after production, and outside is very cold, they have no time for cooling down. The water condense will be formed on their surface. By default, the corrosion phenomenon is favoured.
Due to the fact that for paper, in 30 minutes after packing, the molecules are already on the product, this one is recommended in case the time between packing and transportation is short and the products need immediate protection.
Because the anti-rust paper allows the humidity transfer, for sea shipping is recommended for this one to be used together with the VCI corrosion inhibiting polyethylene film. The packaging where the products wrapped in paper are placed, have the exterior protected with foil.
Applications:
Applications:
3. Water-repellent anti-corrosion oils
Ferrous metals, which are prone to atmospheric corrosion and need protection during storage and use. Petroleum based rust preventives, having ease of application and removal, are preferred for semi-permanent protection. If such Rust Preventives have DE-watering characteristics, they are ideal for inter-process rust protection.
Water-repellent oils for anti-corrosion protection of metallic parts. For use after soluble machining oils, soluble metal-forming oils.
Protection against corrosion of metallic parts is essential. The use of water-repellent oils allows water to be driven out of the metallic parts.
Water-repellent protection oils are recommended when the upstream process lubricants are water based, for example after use of soluble machining oils, or soluble metal-forming oils for the manufacture of tubes, bars and profiles.